Nature of cobalt species during the in situ sulfurization of Co(Ni)Mo/Al₂O₃ hydrodesulfurization catalysts.

ABSTRACT: The evolution in local structure and electronic properties of cobalt was investigated during in situ sulfurization. Using a combination of 1s X-ray absorption (XAS) and 1s3p resonant inelastic X-ray scattering (RIXS), the valence, coordination and symmetry of cobalt ions were tracked in two cobalt-promoted molybdenum oxide precursors of the hydrodesulfurization catalyst system, namely Co-Mo/Al₂O₃ and Co-Ni-Mo/Al₂O₃. Extended X-ray absorption fine structure shows that the Co-O bonds were replaced with Co-S bonds as a function of reaction temperature. The cobalt K pre-edge intensity shows that the symmetry of cobalt was modified from Co³⁺ O_h and Co²⁺ O_h to a Co²⁺ ion where the inversion symmetr

SUBMITTER: Al Samarai M 

PROVIDER: S-EPMC6510205 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature